Guillotine for cutting webs



June 13, 1967 F. F. BROCKMULLER 3,324,752

GUILLOTINE FOR CUTTING WEBS Filed Aug. 11, i965 FIF/idrici lr'ockfmlliller arneys United States Patent O 3,324,752 GUILLOTINE FOR CUTTING WEBS Friedrich Franz Brockmiiller, Lengerich, Germany, assignor to Windmoller Sr Hoischer, Lengerich, Germany Fiied Aug. 11, 1965, Ser. No. 478,844 Claims priority, application Germany, Nov. 30, 1964, W 38,063 Claims. (Cl. 83-328) This invention relates to a guillotine for cutting webs, particularly of plastic material sheeting and paper, in which guillotine each of the cooperating knife beams, which carry the knives, extends transversely to the direction of the advance of the web and revolves around an axis which is spaced from the web to sever sheets from the continuously moving web, said knife beams being guided parallel to themselves with the knives in a position at right angles to the plane of the web by means of a parallel-holding mechanism. With this arrangement and guidance of the knives, the sheets can be severed from the continuously advancing web by a smooth cut giving neat edges, as a cut with scissors. It has now been found that the backlash in the bearings for the journals of the knife beams and between the various gears of the parallelholding mechanisms may result in an inaccurate guidance of the knives. As the knives must be moved very closely past each other in order to perform a cut like that of scissors, an inaccurate guidance may cause the knives to strike on each other rather than moving past each other in performing the cut. This may result in the destruction of the knives and other sensitive parts of the guillotine so that the production is interrupted for a prolonged time.

According to the invention, these disadvantages are avoided in a guillotine of the type defined initially hereinbefore in that each knife beam has at least one guiding element disposed laterally beside its knife, and the guiding elements on the knife beams are oppositely arranged, and as the knife beams approach each other the guiding elements interengage and guide the knife beams during the cutting operation. The provision of the guiding elements disposed outside the area of the web enables a mutual guidance of the knife beams which carry the two knives so that any backlash which may be present in the drive and the bearings of each knife beam is rendered ineffective because the two parts which cooperate in performing the cut mutually adjust themselves to the correct position, in which the knives slide on each other during the cutting operation.

According to the invention, one of the cooperating guiding elements may consist of a guide bar which has a guiding surface that is substantially at right angles to the plane of the web, and the other guiding element may consist of a roller, which is rotatably mounted on the associated knife beam and is preferably formed by the outer race of a radial anti-friction bearing. The use of rollers which roll on guide bars and are suitably mounted on revolvable elements minimizes the frictional resistance involved in the cooperation of the guiding elements and avoids a premature wear thereof. In a preferred embodiment of the invention, each knife beam has close to one end two forked guide bars, which are staggered relative to each other in the longitudinal direction of the beam, and two radial bearings, which are related to each other in accordance with the staggering of the guide bars, are mounted at the other end on the journal of the knife beam, the guide bars of each knife beam coopertaing with the bearing races of the other knife beam. In this arrangement a most reliable, mutual guidance of the knife beams is ensured, and a wear of the guide bars and antifriction bearings is avoided, because one bearing can rotate in the clockwise sense and the other in a counterclockwise sense when the anti-friction bearings are in engagement with the guide bars. In this way, any backlash between the guide bars and the anti-friciton bearings can be avoided. If the guide bars were not staggered, but arranged like a fork, only one anti-friction bearing could be used, which would then have to be kept clear of one of the guide bars, even though this clearance may be very small. Otherwise, if both guide bars were in engagement with the bearing, there would be only sliding friction resulting in a great wear of the bearing. In the preferred embodiment which has been described, each guide bar bears unilaterally on the associated radial bearing so that a detrimental effect of the internal backlash of the bearing is also prevented.

To enable also a compensation for any difference between the internal backlash of the various anti-friction bearings, the position of the guiding surfaces may be variable according to the invention in the transverse direction of the knife beam by the provision of shims between the knife beam and the part for mounting the guide bar. An addition or removal of such shims Will then enable an exact adjusting of the guide bar in accordance with the anti-friction bearing associated with it and to the pressure exerted by each guide bar on the associated anti-friction bearing.

For a further improvement of the guidance of the knives, the invention proposes to eliminate also the backlash between the gears of the parallel-holding mechanisms. For this purpose, that gear of each parallel-holding mechanism which is stationary in operation is angularly adjustable when the guiding elements are interengaged and said gear can be clamped against the machine frame. An angular adjustment of this gear by a very small amount When the machine is at a standstill will result in a mutual clamping of the gears of this parallelholding mechanism so that any backlash which previously existed between them is eliminated. In the resulting position, the gear which is stationary during operation is then firmly connected to the machine frame, e.g., by means of a clamping ring. As a result, the interengagement of the guiding elements will Cause a mutual clamping of the gears of the parallel-holding mechanisms so that the knife beams which guide each other are held Without backlash at both ends during the cutting operation.

Finally, it is desirable according to the invention to provide knives which have slightly rounded entering corners because this will also facilitate a satisfactory movement of the knives past each other.

An illustrative embodiment of the invention Will be described more fully hereinafter with reference to the drawing, in which:

FIG. 1 is a longitudinal sectional view showing a guillotine which is provided wiht the guiding device according to the invention;

FIG. 2 is a sectional view taken on line II-II in FIG. 1;

FIG. 3 is a sectional view taken on line III- III in FIG. 1; and

FIG. 4 shows a modification of a detail of the guide device according to the invention.

Two shafts 3 and 4, which are arranged one vertically over the other, are rotatably mounted in two walls 1 and 2 of a machine Iframe. One of these shafts, for instance the shaft 3, is coupled to a drive, not shown, and imparts rotation to a pair of gears 5, 6, which are firmly connected to the shaft. The rotation of the gears 5 and 6 is transmitted to gears 7 and 8, which are nonrotatably connected to the shaft 4. Journals 9 are rotatably mounted in the gears 5 and 6 and carry a knife beam 10, which is provided with a lower knife 11. Journals 12 are rotatably mounted in the gears 7 and 8 and carry a knife -beam 13 provided with an upper knife 14. Dur- Patented June 13, 1967V ing a rotation of the pairs of gears 5, 6 and 7, 8 in the direction which is indicated by arrows in FIG. 2, the lower knife 11 and the upper knife 14 are held parallel to each other in a position at right angles to the plane Z1 of the web (FIG. 2) by parallel-holding mechanisms, which are composed of gears -17 and 18-20, respectively. In the instantaneous position of the knives 11 and 14 shown in FIGS. 1 and 2, a cut similar to that of scissors is performed through a web which is continuously advanced in the plane 21.

By means of a screw 24, which extends through the lower knife beam 10, two guide jaws 22 and 23 are secured to this knife beam at that end thereof which is remote from the parallel-holding mechanism 15 to 17. Each of the guide jaws 22 and 23 comprises -an extension, which forms a guide 'bar 25 or 26. As is apparent from FIG. 3, the guide bars 25 and 26 are relatively staggered. In the instantaneous position which is shown, each of them lies on one side of one of two anti-friction bearings 27 and 28, which are mounted on the journal 12 that is adjacent to the parallel-holding mechanism 18 to 20. Similarly, two guide jaws 29 and 30 are secured by a screw 31 to that end of the upper knife beam 13 which is remote from the parallel-holding mechanism 18 to 20. Just as the guide jaws 22 and 23, the guide jaws 29 and have two guide bars 32 and 33, which are relatively staggered and each of which is arranged to engage on one side of one of two anti-friction bearings 34 and 35 provided on that journal 9 which is disposed adjacent to the parallel-holding mechanism 15 to 17. These guide bars 32 and 33 together with the guide bars 25 and 26 ensure a guidance of the knives 11 and 14 when the knife beams 10 and 13 are in the position which is shown in the drawing and in which a cut through the web is effected.

Shims 36 are provided between each guide jaw 22, 23, 29, 30 and the respective knife beam 10 or 13. Such shirns may be added or removed to effect an exact adjustment of the guide bars 25, 26, 32, 33, which are integral with the respective guide jaws, so that these bars will match the internal backlash of the respective anti-friction bearing.

To eliminate the backlash between the gears 15 to 17 and 18 to 20, that gear 17 or 20 of the parallel-holding mechanisms, which is stationary during operation, is angularly adjusted by means of the idler 16 or 19 against the gear 15 or 18, which is secured to the respective journal. During this operation, the journals 9 and 12 assume the position which is shown in the drawing and in which they are mutually held by the guide jaws so that the .gears 15 and 18 are also held against rotation. This results in a mutual clamping of the gears. The gear 17 or 20 is then firmly connected to the wall 1 or 2 of the machine frame by means of a clamping ring 37 (FIG. 4) in the position to which it has been moved by the angular adjustment. The elimination of the backlash between the gears of the parallel-holding mechanisms ensures a further improvement of the guidance of the knives.

The backlash between the gears of the parallel-holding mechanisms may alternatively be eliminated in that the journals 9, 12 when they are in the position shown in the drawing, as well as the gears 15 and 18 secured thereto, are angularly adjusted by the gears 16 and 19 against the gears 17 and 20 secured to the machine frame. This angular adjustment may be effected by a corresponding lateral displacement of the guide jaws by means of the shims and results also in a mutual clamping of the gears during the cutting operation so as to ensure a positive guidance of the knife beams. This arrangement may involve a slight canting of the knife beams. Whereas clamping rings for securing the -gears 17 and 20 to the machine frame are not required and these gears may be directly connected to the walls of this frame (see FIG. 1), in this arrangement, the same has the disadvantage that the knives must be subsequently readjusted in the knife beams, which may be canted, to ensure that the knives slide on d each other in a position at right angles to the plane of the web during the cut.

As the cut through the web begins at the corners 38 and 39 of the knives 11 and 14 and the knives enter the web at this point, the corners 38 and 39 are suitably slightly rounded as an additional feature to ensure a satisfactory movement of the knives past each other.

What is claimed is:

1. A guillotine for cutting webs, particularly of plastic material sheeting and paper, comprising a pair of cooperating knife beams each carrying a knife and extending transversely to the direction of the advance of the web and revolving around an axis which is spaced from the web to sever sheets from the continuously moving web, parallel holding means guiding said knife means parallel to each other with the knives in a position at right angies to the plane of the web, guiding elements carried on each knife beam and so arranged that as the knife beams approach each other they cooperatively interengage and guide the knife beams during the cutting operation, at least one of said guiding elements on each knife beam being disposed laterally beside its knife and consisting of a guide bar having a guiding surface substantially normal to the plane of the web and cooperatively interengaging a guiding element consisting of a roller.

2. A guillotine for cutting webs, particularly of plastic material sheeting and paper, comprising a frame, a pair of cooperating knife beams each carrying a knife and extending transversely to the direction of the advance of the web and revolving around an axis which is spaced from the web to sever sheets from the continuously moving web, parallel holding means guiding said knife beams parallel to each other with the knives in a position at right angles to the plane of the web, guiding elements carried on each knife beam being so arranged that as the knife beams approach each other the guiding elements cooperatively interengage and guide the knife beams during the cutting operation, said parallel holding means including a number of gears, a gear means, and a clamping means, said gear means being stationary when said guillotine is in operation and angularly adjustable when the guiding elements are interengaged to take up any backlash that might exist between said gears, said clamping means being provided to maintain said gear means stationary while the guillotine is in operation by clamping said gear means against the frame of the guillotine.

3. A guillotine according to claim 1, characterized in that said roller is formed by the outer race of a radial anti-friction bearing.

4. A guillotine according to claim 1, characterized in that each knife beam has disposed laterally to one side of its knife a forked guide member the legs of which are guide bars and are staggered in the longitudinal direction of the beam, and disposed laterally to the other side two radial bearings, with the radial bearing on one beam cooperating with and registering with the guide bars on the other beam.

5. A guillotine according to claim 4, characterized in that the position of the guiding bars is variable in the transverse direction of the knife beam by the provision of Shims between the knife beam and the forked guide member mounted thereon.

References Cited UNITED STATES PATENTS 1,989,012 1/1935 Kalko 83-328 3,066,542 12/1962 Einhiple a 83-328 FOREIGN PATENTS 906,536 3/1954 Germany.

ANDREW R. JUHASZ, Primary Examiner.

WILLIAM W. DYER, J R., Examiner.

L. B. TAYLOR, Assistant Examiner. 

1. A GUILLOTINE FOR CUTTING WEBS, PARTICULARLY OF PLASTIC MATERIAL SHEETING AND PAPER, COMPRISING A PAIR OF COOPERATING KNIFE BEAMS EACH CARRYING A KNIFE AND EXTENDING TRANSVERSELY TO THE DIRECTION OF THE ADVANCE OF THE WEB AND REVOLVING AROUND AN AXIS WHICH IS SPACED FROM THE WEB TO SEVER SHEETS FROM THE CONTINUOUSLY MOVING WEB, PARALLEL HOLDING MEANS GUIDING SAID KNIFE MEANS PARALLEL TO EACH OTHER WITH THE KNIVES IN A POSITION AT RIGHT ANGLES TO THE PLANE OF THE WEB, GUIDING ELEMENTS CARRIED ON EACH KNIFE BEAM AND SO ARRANGED THAT AS THE KNIFE BEAMS APPROACH EACH OTHER THEY COOPERATIVELY INTERENGAGE AND GUIDE THE KNIFE BEAMS DURING THE CUTTING OPERATION, AT LEAST ONE OF SAID GUIDING ELEMENTS ON EACH KNIFE BEAM BEING DISPOSED LATERALLY BESIDE ITS KNIFE AND CONSISTING OF A GUIDE BAR HAVING A GUIDING SURFACE SUBSTANTIALLY NORMAL TO THE PLANE OF THE WEB AND COOPERATIVELY INTERENGAGING A GUIDING ELEMENT CONSISTING OF A ROLLER. 